Wire stitching machine



April 1952 J. a NASMITH ET AL WIRE STITCHING MACHINE 5 Sheets-Sheet 1 Filed Oct. 50, 1947 FIG./.

April 22, 1952 J. l. NASMITH ET AL 2,594,201

WIRE STITCHING MACHINE Filed Oct. 30, 1947 3 Sheets-Sheet 2 K NASMITH ET AL.

April 22, 1952 WIRE STITCHING MACHINE 5 Sheets-Sheet 3 Filed 0015. 50, 1947 F/GZ.

Patented Apr. 22, 1952 WIRE STITCHING. MACHINE JohnIrving'Nasmith and Wilfred Kirby, London, England, assignorsto Vickers-Armstrongs Limited, London, England, a. company of Great Britain.

Application October 30, 19:47, Serial" No. 783,200

. In GreatBi-itain. September 25, 1946 Section Publi'c'Law 690,,August 8,.1946; Patent. expires Septemher'25 1966 15 Claims.

I This: invention relates to wire feeding, mech anism and is concerned more particularly with controlling the wire feed in wire; stitching ma.- chinesfor the forming and driving single: or, double stitches.

Broadly, the invention consists in the provision of wire' rippeis associated with the wire feeding elements and adapted to grip the. wire during the feeding stroke, and further wire grippers adapted to hold the wires after-- feeding; is; complet'e whilst the fed wires are being severed and the wire feeding; elements are returning to the position forfeeding a further'l'engthof wire the various wire grippers being operated in the desired sequence and; timed relationship: to ensure positive control; of the wire. or; wires at alltime in the working cycle from leaving, the spool; until they are delivered to the stitch forming mechanisnr.

. Furthermore: the invention; includes, in, doublest-itch feed mechanism, the provision for independently operable setsof grippersior each wire; and means whereby either wiremade be: immobilised at will 01" by automatic control so that either orboth wiresmaybe fed attire given. times to: place single and. double stitches in various selected sequences; as best suited; to. the work being operated. on, all these controls: being provided in. such a form. as to be independent. ofzthe particular setting for length. of thewiresa being fed.

By the employmentof mechanism according to the invention veryreliable; and. accurate; wire feeding is attained at the highest speediss.-with the, minimum possible wear of the. wire, feedin -elements, and useful alternative methods of'placments which prevent return motion of the wire during the return motion of thewire feeding; elements, and herei-natter referred to asnon-return grippers must be mechanically opened. The gripis thus transferred from the non-return grippers to the wire feed grippers whilst those .and, the wire are stationary, and onthe forward motion of the wire-feeding elements the wires are. fed freely forward. (,2) After the conclusion of thezfeeding stroke of'the wire feeding elements and during a stationary period prior to the return of the wire feeding, elements, the non-return grippers. are closed andjthe wire feed grippers opened, the wire grip control now passing from the feeding elements, to the non-return elements; during. the. return motion of the wire feeding elements the. wire feed grippers are. thus completely free of the wire and remain so till the wire, feeding elementsfare again stationary and the nextclosure. take place prior to. the ensuing feeding stroke. (3) The wire gripper control means to. operate the grippers as described must be effective whatever the length of wire being fed within a. given range of adjustment of the length of fOOtlm' (4 In. double-stitch feed mechanism, the, wire gripper control means to operate the grippers in the manner described must baconstructed to operate. the respective grippers. of both. wires, toobtain simultaneous feed and must be adaptable to operate when required only the wire feed grippers and non-return grippers of either one of the wires. (5) Byvirtue of theconstruction disclosed in the previous requirement, if timed independent means the gripper actuating; mechanism is prevented from acting on the grippers pertaining to one of the wires and this latter wire is. held continuously by its nonreturn gripper, whilst its feed gripper, is inoperative; the said wire will be immobilised and onlysinglestitcheswill be. driven from the o-ther wire until the original control is restored and both wires are again fed simultaneously. If the aboverequirement is satisfied, suitable independout control mechanism may be employed to place any desired sequence of double or single stitches. The feeding of wire from a. spool is accomplished either by grip between actuated feed. rollers; or;discs, orby gripper jaws guided in a straight or arcuate path. The invention may be utilised-in any of these cases. It will be under- Stood however that the construction will. differ in, detail with the range of adjustment of wire feed requiredand; the type of wire, feeding adopted without however varying in. principle or function. l I

By way of an example, an embodiment of the invention will now be described in more detail withreference to the accompanying drawings. In -this example theinvention is described as applied to; a, double stitch feed mechanism with arcuately.guidedgrippers.

In. the accompanying drawings: Figure -1 isca partial. front elevation, partly. in

-cession instead of simultaneously.

Figure 2 is a sectional end elevation on the lin XX of Figure 1 in the direction indicated.

Figure 3 is a partial sectional end elevation on the line Y-Y of Figure 1 in the direction indicated.

Figure 4 is a partial plan view on the line Z-Z of Figure 1.

Sufficient of the machine frame work and contiguous mechanism is shown in the figures, to make clear the relationship of the mechanism to be described.

Referring more particularly to Figures 1 and la,

rotating in the direction indicated by the arrow .0

in the wire stitching machine frame I, is a compound cam 2, the outer periphery 3 of which constitutes a cam surface for operating the wire gripper control means and the wire cutting and subsidiary mechanism to be described later. The periphery 4 of. the rotating cam operates the wire feeding element which is in the form of a feed lever I2. The stitch forming and driving eleagainst the slider B by a spring I06 resiliently con necting the slotted stem l l to the gripper 10.

The wire feeding means comprise a wire feed lever l2 pivoted on a fixed axis 13 in the machine frame and actuated by the cam periphery 4 through a cam roller 4a. The feed lever is urged clockwise by a spring I4. The lower arm of the feed lever I2 is adapted directly to carry the wire feeding grippers, of which there are two, each adapted to operate on one of the wires with its respective non-return gripper. The amount of wire fed in each stroke is regulated by the position in which the bracket 9a is set, this bracket being ments are also driven from the cam 2, and the general arrangement of these elements with respect to the cam may be substantially as described in British Patent Specification No. 361,633. The stitch forming element is indicated at 5.

Sliding in the stitching head frame, parallel.

to the stitch forming element 5, is a slider 6, which is also referred to as the wire gripper control element. This element is shown in the Figure 1 in section with its front connecting wall removed.

The slider 6 is provided with a pin and cam roller I working in conjunction with the cam periphery 3 and actuated thereby in the manner to be described later. The cam roller 1 is urged against cam periphery 3 by a compression spring 6a and plunger 6b abutting at the lower end against a fixed part of the frame. The slider 6 carries a striker plate 8 rigidly secured thereto. The element 6 is hollowed out at the back to admit a forwardly projecting part of a horizontally adjustable sliding plate 9. This plate carries the upper and lower wire cutting knives indicated respectively by 9b and 9c and their supporting means and also a pair of non-return wire grippers it) each adapted to hold one of the wires during the return motion of the wire feeding element. The

relative disposition of the wire cutters and thecutting element is duplicated and the upper cutting knife is adapted to out both wires-if these are presented to it, preferably in immediate suc- The nonreturn wire grippers iii are independently slidable in the extension of plate 9 as shown in Figure 3, and have stems I I projecting thorugh the control element Bfor independent actuation as described later. Each stem 1 l is capable of movement with respect to the gripper I0, to an extent limited by a pin IOa-and a slot Iflb, and is normally pressed wires.

rigid with the plate 9. The position of bracket 9a determines also the position of the cut-off knives relative to the stitch forming and driving elements, and the position of an initially adjusted set screw I5, against which impinges a stop [6 mounted on the feed lever i2, and therebydetermines the free motion of the feed lever 12 under the action of the spring 14. The wire feeding means, also comprise a guide plate [1 having slots Ila. for two wires, a wedge shaped channel 18 on either side of the lever l2, and two slotted grippers 19 working in the channels I8 and adapted to move on pins l9a. carried by actuating levers 20. The levers 20 are separately pivoted on a pin 21 secured in the lever i2 and normally close the grippers under the influence of the springs 22. v To actuate the wire feed grippers the following mechanism is provided. Mounted on a fixed pivot 23 in the stitching head are two independent two armed levers 24 one on either side of the lever [2. A pin 25 in each of these levers serves to pivot links 26 the lower ends of which are provided with slots 21 embracing the pivot pin 2| of the levers 20 on either side of the lever i2. The links 26 alsocarry lugs 26a for setting screws 28, the ends of which abut against projections 20a of the levers 20. The pendant arm of each lever 24 has a projection 24a to co-act with the striker plate 8 secured to thewire feed control elementrfi. The action of the mechanism so far described is as follows, and it will be understood that the action takes place similarly whether either or both wires are threaded up, in the latter case a succession of double stitches'being formed and driven. In the position shown in Figures 1 and 1a, the forward stroke of the wire feed lever l2 has been completed, the roller 4a being on the highest part of the cam 4. Also, the non-return grippers II) have been pressed on to the wires D by the first rise 3a of the cam periphery 3 having depressed the roller 1 and hence the slider 6. Before the cam periphery 4 begins to allow the feed lever to return; the cam periphery 3 further depresses the slider 6, so that the striker plate 8 moves the levers 24 clockwise about 23 and therefore raises the links 26. By the medium of the setting screws return stroke of the feed lever [2, the wires being meantime under control of the non-return grippers 10, and held immovable thereby. The cam peripheries are designed such that when the feed lever 12 is fully returned (at the longest feed setting obtainable by adjustment of plate 9) the feed'lever is stationary for a period before commencing the forward stroke. During this period the projection 3b of the cam periphery 3 further depresses the control member 6, causing the wire cutters 9b and 9c actuated thereby to cut the Immediately thereafter the cam projection 31; allows theful'lreturnofthe slider B, which return motion first restoresthe wire feed grippers l9 into action on thewires', through the'levers 24, links 26 and springs 22, and then opens'the-nonreturn grippers H). The wires are now controlled only by the'wire feed grippers l9 and the wire feeding stroke commences. When this, is com plete the portion 3a of cam periphery 3 again actuates the slider 6 to close the non-return grip pers it, both wire feed grippers and non-return grippers being now temporarily in action during a pause of the lever [2 at the end of the' feeding stroke. y'lhe position shown in Figures-1 and in has now been regained and: the cycle commences again;

The pivot center 25 is sodisposed that up tothe limiting position of the feed length adjusting bracket 9 farthest away from the stitching. centre line; the wire feed grippers [9- remain clear of the wire during the entire return strokeuntilrel'eased by" the cam' projection 312:

- Ingeneral double stitches are only required in a specified sequence interspersed with single stitches. To enable either" wire of a double wire stitcher to" be put out of action as" and when required, the" following" additional feed selector mechanism is provided.

Referring more particularl'y'to' Figure 4 a fixed pivot center 25 is provided on the stitching; head framework, on which is pivoted in a horizontal plane a double armedleVer-ZQ. The forward extremity" of this is provided with two longitudinal slots 29a in which a double pronged fork 30" is adjustably secured by screws 2%. The prongs areprovided with sloping end-faces 31;, and these are adapted to engagethe ends of-the horizontal arms 24b of the respective levers" 24 when the lever 29' is actuated.

When the fork 3llengages neither of" the? levers 24' no selective control is exercised and the" sequence of double stitches already described takes place if both wires have been threaded up. When one prong of the fork is set to engage the rear lever 24', as shown in Figure 4;. the rear wire is immobilised, whilst if set to engage the front lever the front Wire will be the one affected; Referring back to Figures 1 and fa, andassumingthe member. 30 is, set as in Figure 4"; when the element 29' is actuated toli'nscrt the parallel" part of the prong beneath the, projection 24b. off the rear lever 24, the corresponding) feed, wire gripper 19. is openedthrough its link 26, and control of this gripper from the slider Bthro'ugh the striker plate 8 ceases. Further, by means of the projection 240 of the rear lever 24 and the projecting stem H of the, rear non-return gripper HI}. the latter is kept closed as long asthis'position of the fork 30 is maintained. This condition applies within the range of adjustment of plate 9. In other words the rear'wire is no longer fed forward and remains held by the respective? non-return gripper lllwhich prevents anydisplacementthere of. This condition is maintained until normal control is restored by the reverse movement of the lever 29, which allowsthe lever 2 4*to' return to its normal position where-itis under theinfiuence of the feed control member 6.

The lever 29 maybe manually operated, or alternatively it may be coupled up tostitch setting mechanism so as to be-automatically operated after a givensequence of stitches; Forexample such automatic operation may be' realised by coupling the lever 29 through a member 32 to the mechanism. described in: the co-pending patent application No."782,822;

It will be understood that the wire'feed mechanism according to the invention may be employed in wire stitching machines using; forms of grippers other than those described above, for l example in machines using feed wheels or discs tofeed the wire, the carriers for one of eaclr pair of discs would be operated to put thediscs, whilst these are stationary, in and out of engagementwith the wire in a functionally similar manner,

' thefeed discs being in this case the wire grippers;

Furthermore it is to be understood that al though the invention has been described herein: as applied to a stitching machine it is not limited in this respect but only in so far as definedinltheappended claims. it

We claim: v

1. Mechanism for intermittently feeding wire comprising in combination a supporting frame-,a

wire feeding element, a driving cam for causing said element to perform a feeding stroke and a return stroke with a stationary dwell period. be fore each'change'of direction, a wire feed gripper supported by said feeding element and for grip. ping thewire during the feeding stroke, a. nonreturn gripper for holding the wire stationary during the return-stroke, a wire gripper control element common to both the feed gripper and non-return gripper, a cam follower on said common control element, a cam periphery associated with 'saiddriving cam engageable with said follower to displace said control element in timed relationship with-said wire feeding element, and means for operatively connecting the control element to both the feed gripper and non-return gripper, said cam periphery being shaped to displace the control element to open and close the respective grippers during the respective eta-'- tionary dwell periods of the wire feeding element to ensure that full control of the wire is always taken over by one of the grippers before being relinquished by the other gripper;

2. Mechanism for intermittently feeding wire comprising in combination a supporting frame, a wire feeding element, a driving cam forca-using said element to perform a feeding stroke and a return stroke with a stationary dwell period before each change of direction, a wire feed gripper supported by said feeding element. and :for gripping the wire during the feeding stroke, a nonreturn gripper for holding the wire stationary during'the return stroke, a wire gripper control element common to both the feed gripper and the non-return gripper, a cam follower on said common control element a cam periphery associated with said driving cam engageable with said follower to displace said control element in timed relationship with. said Wire feeding eie ment, means for operati'vely connecting the-com mon control element to both the feed gripper and the non-return gripper respectively at pres" determined times during each cycle of movement of the wire feeding element, and parts on. said canrperiphery for displacing the control element and causing the latter to actuate the respective grippers so that control of the wire is transferred from one gripper to the other during the respecfeeding stroke and a return stroke with a stationary dwell period; before each change of direction, a wire feed gripper supported by said feeding element and for gripping the wire during the feeding stroke, a non-return gripper for holding the wire stationary during the return stroke, a vertically displaceable gripper control element common to both the feed gripper and the non-return gripper, means for providing operative connection between said common control element and the wire feed gripper over the full amplitude of movement of the wire feeding element, said means comprising a lever pivotally mounted in the frame and operable by said control element and a link operatively connecting said lever to the feed gripper, a cam follower on said common control element, a second pe- 8 shaft, a wire feeding element, a periphery on said cam for driving the wire feeding element to per form a feeding troke and a return stroke with a stationary dwell period before each change of direction, a wire feed gripper carried by a spring loaded lever pivotally mounted upon said feeding 7 element, a non-return gripper for holding the riphery on said driving cam engageable with said follower for displacing the common control element along a vertical guide in the frame, the said peripheries of the driving cam being so shaped that the control element is displaced in timed relationship with the said wire feeding element to effect in each stationary dwell period firstly the closing of that gripper which is for element and actuated by lever mechanism pivotally connected to the feeding element, a nonreturn gripper for holding the wire stationary during there'turn stroke, a vertically displaceable igripper control element common to both the feed g'ripper and the non-return gripper, a striker on the control element for actuating said lever mechanism and feed gripper, means for operatively connecting the control element to the non- ,return gripper, fixed vertical guides in the frame for said common control element, a second pe- -riphery on said driving cam for displacing the common control element in said vertical guides against spring pressure and in timed relationship with said wire feeding element, the said lever mechanism providing operative connection between said common control element and the wire feed gripper over the full amplitude of movement ofthe wire feeding element.

5. Mechanism as claimed in claim 4, wherein the levermechanism of the feed gripper comprises a lever pivotaly mounted in the supporting frame, said lever having an arm operable by the striker of the common control element, a second lever operatively connected to said first lever, the

second lever having control of the feed gripper over the full amplitude of movement of the wire feeding element.

' 6. A mechanism as claimed in claim 4, wherein 1" the lever mechanism for actuating the wire feed gripper comprises a lever pivoted in the supporting frame, said lever having an arm operable by the striker of thecommon control element, an in termediate lever pivotally connected to the said first lever and controlling said wire gripper over the full range of movement of the wire feeding element, and a Wire gripper lever connecting said intermediate lever to the wire feed gripper.

7. Mechanismfor intermittently feeding wire comprisingin combination a supporting frame, a drivenshaft, a cammounted on saiddriven wire stationary during the return stroke, a vertically displaceable gripper control element, a striker on said control element, a lever mechanism providing an operative connection between the control element and the wirefeed gripper over the full amplitude of the feeding element, said mechanism comprising a lever pivoted on the frame, an arm on said lever engag'eable by the striker of the common control element, an intermediate arm pivotally connected at one end to said lever and, at the other end, slidably connectedito the spring loaded lever which carries the feed gripper, mean for operatively connecting the control element to the non-return gripper, a second periphery on said cam for displacing the control element against the action of a spring pressed plunger, in timed relationship with the actuation of the feeding element, each of the peripheries of said cam being so formed that the control element is displaced to open and close the respective grippers during the respective dwell periods of the wire feeding elements.

' 8. Mechanism for intermittently feeding wire comprising in combination a supporting frame, a wire feeding element having a cam follower at one end, a driving cam with a cam periphery engageable with said follower for causing said element to perform a feeding stroke and a return strokewith a stationary dwell period before each changeof direction, a wire feed gripper pivotally mounted upon the other end of said element, a displaceable control element operatively connected to the wire feed gripper, a support member mounted within the frame and adjustable in the direction of wire feed, an extension on said support member projecting into the control element, a. non-return gripper slidably mounted in said extension for holding the wire stationary during the return stroke of the feeding element, wire cutters carried by said extension of the support member, a cam follower on said control element, a spring urged plunger for holding said follower in engagement with a second periphery on said-driving cam, parts on said second periphery for depressing the control element against the action of said plunger to cause the common controlelement to operate the wire feed gripper, the non-return, gripper and the wire cutters, the peripheries on said driving cam being so arranged a that the control element is actuated in timed relationship with respect to the wire feeding element to transfer the wire grip from one gripper to the other at intervals falling within the respective stationary dwell periods of thefeeding element and to operate the wire cutters at a predetermined time in the working cycle over the adjustment range of the said adjustable support.

9. The mechanism as claimed in claim 8, comprising in combination, an adjustable stop on said support member, an abutment on the wire feeding element engageable with said stop at the end of the return stroke of said element, and means for adjusting said support member thereby to determine both the position of the wire cutters and also the length of stroke of the wire feeding element. V 7

1t). Mechanism for intermittently feeding wire comprising in combination a supportingframe, a

wire feeding element, a rotatable cam for driving the said element to perform a feeding stroke and a return stroke with a stationary dwell period before each change of direction, a wire feed gripper supported by said element for gripping the wire during the feeding stroke, a non-return gripper for holding the wire stationary during the return stroke, a wire gripper control element common to both the feed gripper and the nonreturn gripper, a cam follower on said common control element, a periphery on said rotatable cam engageable with aid follower for displacing said control element in timed relationship with said wire feeding element, a linkage providing operative connection between common control element and the wire feed gripper over the full amplitude of movement of the wire feeding elements, means actuated by said control element for opening and closing the respective grippers during the stationary dwell periods of the wire feeding element, and wire feed interrupting means comprising a lever pivoted in the supporting frame, an arm on said leverengageable with said linkage to break the operative connection between the common control element and the wire feed gripper without effecting the motion of the wire feeding element and means for causing the said interrupting means to clamp the nonreturn gripper on the wire to immobilize the same.

11. The mechanism as claimed in claim 10, wherein the linkage providing operative connec tion between the common control element and the wire feed gripper, comprises a lever pivotally mounted in the machine frame, an arm on said lever, a striker on said common control element for engaging said arm rocking said lever upon downward displacement of said control element, a second arm on said lever for clamping the nonreturn gripper on the wire to immobilize the r cam for causing said feeding element to perform ,5

a feeding stroke and a return stroke with a stationary dwell period before each change of direction, two wire feed grippers each supported by said feeding element and movable simultaneously in the feed direction by the wire feeding element,

lever mechanism for independently operating the said feed grippers for gripping and releasing the respective wires, two non-return grippers, one

- for each wire, mounted for independent operation for gripping and releasing the respective wires, a

displaceable wire gripper control element common to the wire feed grippers and the non-return grippers, a second periphery associated with said driving cam, a cam follower on said common control element engageable with said second cam periphery for displacing the common control element in timed relationship with the wire feeding element to open and close the wire feed grippers in unison and to open and close the non-return grippers in unison, projections on said cam peripheries for causing the opening, and closing operations to take place during the respective stationary dwell periods of the wire feeding element, wire feed interrupting means comprising a lever pivotally mounted in the frame, a pair of arms on said lever each of which arms is associated with one of the wire feed grippers and its respective non-return gripper, and means for rocking said wire feed interrupting lever to immobilize either one of the wires by clamping the respective non-return gripper on the wire and in the same action removing the respective wire feed gripper from the influence of the common control element.

13. The wire feed mechanism'as claimed in claim 12, wherein the means for establishing operative connection between the common control element and the respective wire feed grippers comprises for each wire feed gripper an independent mechanism comprising a lever pivotally mounted in the frame, a dependent arm on each of said levers, a striker on said common. control element engageable with said dependent arms to operate said levers for normal double wire feed ing, and lateral arms on said levers independently engageable by said wire feed interrupting lever to immobilize one of said mechanisms to provide for single wire feeding.

14. A wire feeding mechanism as claimed in claim 12, wherein the lever mechanism for each feed gripper comprises a lever pivotally mounted in the frame and operatively connected to the respective gripper, a dependent arm on said lever engageable by a striker on the common control element for the normal opening and closing of the gripper, a second arm on said lever engageable with a plunger connected to the respective non-return gripper, and a third arm operable by the interrupting means to cause said lever to open the respective wire feed gripper and to retain it in that position while said plunger is actuated by i motion in a horizontal plane, a double pronged fork carried by said lever, one prong for each lever mechanism, and means for the selective displacement of said lever to cause a prong of said fork to engage the said third arm of the associated lever mechanism and to produce immobilization of the respective wire.

' JOHN IRVING NASMITH.

WILFRED KIRBY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 33,707 Kaiser Nov. 12, 1861 1,059,338 Banner Apr. 22, 1913 1,074,564 Weber Sept. 30, 1913 1,192,481 Weber July 25, 1916 1,495,508 Campbell May 27, 1924 1,655,471 Marceli Jan. 10, 1928 

